Dynamic biasing for true low-voltage CMOS class AB current-mode circuits

Abstract

This paper presents a dynamic biasing approach for continuous-time CMOS class AB current-mode circuits. The method allows low voltage circuits to be implemented whose supply requirements are restricted to one threshold voltage plus two saturation voltages. Fundamental limitations of the approach are analyzed and found to be compatible with a wide spectrum of analog applications, some of which are briefly discussed. A complementary current mirror, a current comparator, and a current amplifier were designed using the proposed technique. SPICE simulations using a 0.8-/spl mu/m process are provided, which confirm the overall performance of these circuits especially in terms of low-voltage capability and speed without compromising linearity.